1. Field of the Invention
The present invention relates to an effector, and relates, more particularly, to a circuit structure and a physical structure of an effector that is externally connected to a guitar amplifier or an acoustic mixer to provide a predetermined acoustic effect.
2. Description of the Related Art
FIG. 1 shows one example of a connection structure of a guitar using a conventional effector.
In FIG. 1, a connection cable from a guitar 1 is connected to an input terminal of an effector (Fx) 2, and an output terminal of the effector 2 is connected to a terminal A of a guitar amplifier 3 using another cable.
The effector 2 is a digital effector that has recently become common. An electrical signal from the guitar 1 (or a microphone or the like) is converted into a digital signal by an A/D converter that is provided at the input terminal side of the effector 2.
This signal is digitally processed by an internal DSP (digital signal processor) to have a predetermined acoustic effect such as a distortion, a compressor, a reverb, and a chorus, for example. Then, the signal is converted into an analog signal by a D/A converter that is provided at the output terminal side of the effector 2, and this analog signal is input to the guitar amplifier 3.
As explained above, the conventional effector 2 has an input terminal and an output terminal independently. Therefore, when the effector 2 is used to play the guitar 1, two cables are necessary, one for connection between the guitar 1 and the effector 2, and the other for connection between the effector 2 and the guitar amplifier 3. When a plurality of effectors are used to play the guitar, more cables become necessary to connect between these effectors.
Consequently, the above connection had a problem that the cable wiring becomes complex. The use of a plurality of cables also had a problem in the sound quality aspect such as increase in noise or degradation of a high-frequency sound characteristic. It should be taken into account that many guitarists prefer connecting a guitar directly to a guitar amplifier using a cable, and tend to dislike degradation of the sound quality due to the existence of complex cables and electronic appliances like effectors.
Although not shown in the drawing, when a mixer is used, it is necessary to connect effectors to individual tracks of the mixer. For this purpose, send/return terminals (two terminals) become necessary for each track at the mixer side to connect between the mixer and each effector. This structure constrains external sizes of the mixer itself, and increases the manufacturing cost of the mixer. As a result, the use of the conventional effectors has also affected other units that are connected to the effectors.